For those willing to build Classilla, I have never done it, I will probably never do it, given the fact that I do not have the knowledge to do so properly. But here are the steps (from what I've gathered so far):
0. Have a very powerful OS9 machine ready to get used as an environment to build;
1. Get the Classilla source code (it's available on
SourceForge);
2. Get CodeWarrior 7.1 (it's available on
Macintosh Garden);
3. Follow the wiki steps on how to build Classilla (
Click here);
4. Good luck. If you have luck, don't forget to rebrand it since it is not an official Classilla build.
Idea: I don't know to which extent Roytam1 went with his
fork of Classilla (he told me that he does not have PPC toolchains to do so, and as such, he never tried to do a build and as far as I know, he does not plan to do a build) but he has a fork with possible TLS1.2 experiments here. You probably have to replace (not merge) the files with the 9.3.3 source files (since he hasn't updated it for the last 15 months) and you must make sure everything is in its right place.
Good luck. I won't even try given that I do not own a PowerPC machine and I have only a very small QEMU PPC VM running OS 9.2.2 just for fun (I am just a retro enthusiast with interest on software side, not much on hardware side, and as such, I have interests on System 7, OS 9, and early OS X builds).